ST. PAUL, Minn. (AP) – Minnesota health officials say the state is dealing with a rising number of whooping cough cases this year.

The Department of Health says in the first five months of 2012, 670 cases of pertussis were confirmed. That’s more than the total number of cases for all of 2011. In the Twin Cities metro, the most populous county, Hennepin, leads the way with 219 cases.

Mayo Clinic pediatric infectious disease specialist Dr. Thomas Boyce tells KARE-TV (http://kare11.tv/JiJfv4) the hospital usually does about a dozen pertussis tests per week. In the past three weeks, that number has ranged from 41 to 63 tests a week.

For infants, whooping cough is potentially fatal, because they aren’t fully immunized yet. The ailment spreads through sneezing and coughing.